Artificial reflex arc: a potential solution for chronic aspiration. III: Stimulation of implanted cervical skin as a functional graft triggering glottic closure in the canine.

Stroke often impairs the ability of the vocal cords to close during deglutition, resulting in aspiration. The current study is a further advance on the application of the concept of an artificial reflex arc during swallowing. The second and third cervical branches were bilaterally isolated in four dogs and baseline sensory nerve traffic was detected via tripolar perineural electrodes. Cervical skin pressure-induced suprathreshold signals were used to trigger vocal cord contraction via bipolar electrodes passed around the recurrent laryngeal nerves. Skin subtended by the cervical nerves was implanted over the lateral aspect of the pyriform sinuses for 1 week. After reexploration, glottic closure was verified on videotape as surges in sensory nerve traffic were induced by mechanical stimulation of the pharynx. The possibility of artifactual stimulation was ruled out by lack of electrode motion during pharyngeal stimulation, spontaneous firing in the sensory nerve during light anesthesia, and sensory frequency differing from ambient 60-Hz noise. This article introduces the concept of autogenous functional graft as a basis for afferent information in electronic systems for dynamic rehabilitation of swallowing disorders.